Category zeolites Space group P21/m | Crystal system Monoclinic | |
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Formula
(repeating unit) (Ba0.5,Ca0.5,Na,K)5Al5,Si11O32·12(H2O) Crystal class Prismatic (2/m)
(same H-M symbol) | ||
Harmotome is a mineral, one of the rarer zeolites; a hydrated barium silicate with formula: (Ba0.5,Ca0.5,Na,K)5Al5,Si11O32·12(H2O). It forms vitreous white well defined monoclinic crystals, often associated with calcite and other zeolites. It has a Mohs hardness of 4 to 5 and a specific gravity of 2.44 to 2.5.
Name and discovery
Named from the Greek words harmos (a joint) and temseis (I cut) because the pyramid divides parallel to the plane that passes through the terminal edges. It was first described in 1801 from an occurrence in the Harz Mountains, Lower Saxony, Germany.
References
Harmotome Wikipedia(Text) CC BY-SA